Metal panels

ABSTRACT

A furnace roof construction for accommodating rows of headers located above the roof and the ends of upright tubes extending through the roof for connection to the headers. The roof construction having horizontally extending tubes arranged at the bottom of the roof and including a plurality of expandible metallic panels covering the headers and the ends of the upright tubes attached thereto and a portion of the horizontally extending tubes and also including a plurality of metallic casing sheets extending parallel to and covering the remaining portion of the horizontally extending tubes. Each of the expandible panels having generally flat planar surfaces, some of which cooperate to form an enclosure of generally rectangular crosssection extending along the panel and at least one pleated portion of generally triangular cross-section extending along the panel and enclosure in a direction transversely of the enclosure.

O United States Patent [191 v [111 3,802,853

OConnor Apr. 9, 1974 METAL PANELS Primary E.raminerA. B. Curtis Assistant ExaminerO. F. Crutchfield l [75] Inventor gzgigzz 0 Connor Bmm ey Attorney, Agent, or Fzrm.l. Maguire; Robert J.

Edwards [73] Assignee: Babcock & Wilcox Limited, London,

England [57] ABSTRACT [22] Filed; July 1, 1968 A furnace roof construction for accommodating rows of headers located above the roof and the ends of up- [21] PP 741,757 right tubes extending through the roof for connection to the headers. The roof construction having horizon- [30] Foreign Application Priority Data tall? extlendiiligdtubes alrranlged it the baglom of tire roo an ll'lC u mg a p ura 1ty o expan 1 e meta lC June 30. 1967 Great Britain 30430/67 panels covering the headers and the ends of the p [52] U S Cl 29/183 29/19O right tubes attached thereto and a portion of the hori- [51] Bzzf 5/00 zontally extending tubes and also including a plurality [58] Fie'ld 52/573 of metallic casing sheets extending parallel to and covering the remaining portion of the horizontally extend- 56] References Cited ing tubes. Each of the expandible panels having generally flat planar surfaces, some of which cooperate to UNITED STATES PATENTS form an enclosure of generally rectangular cross- 3,l84,094 5/1965 French Ell al 52/573 X section extending along the panel and at least one 3,273,976 9/1966 Wogerbauer 29/183 X pleated portion of generally triangular cross section 3 299 598 l/l967 3'3O2359 2,1967 extendlng along the panel and enclosure in a direction 3'395438 8/1968 transversely of the enclosure.

5 Claims, 3 Drawing Figures I PATENIEDAPR 9 m4 sum 2 or 2 METAL PANELS This invention relates to panels formed from sheet metal. I

It is sometimes desirable that a panel should be formed from sheet metal and yet be able to expand to some extent in response to forces applied to it mechanically. Such panels may be useful in forming a skin casing, for instance, of a boiler and it is especially envisaged that such a panel would be useful in forming the roof of a boiler.

According to the present invention, there is provided a mechanically expandible panel formed from sheet metal providing two wing portions or base surfaces connected together by a channel or enclosure of generally rectangular cross-section of which the side wall portions or side surfaces are each joined along one edge to an edge of one of the wing portions or base surfaces and along the other edge to one of the edges of the bridge portion or raised surface of the channel, and having a pleat extending transversely across the channel and the wing portions and formed from strips converging towards each other, the parts of the pleat that lie in the wing portions and the bridge portion projecting in one sense from the portions in which they lie and the parts of the pleat that lie in the side wall portions projecting in the reverse sense from those portions.

By way of example an embodiment of the invention will now be described with reference to the accompanying drawings in which:

FIG. 1 shows in diagrammatic plan view a panel formed from sheet metal;

FIG. 2 shown diagrammatically an end view of the panel shown in HO. 1 in the direction of the arrows; and

FIG. 3 shows an transverse cross-section a furnace roof containing two rows of panels such as are illustrated in FIGS. 1 and 2. i

The panel shown in FIG. 1 includes two wing portions or base surfaces 1 connected together by a channel 2. The channel or enclosure 2 is of generally rectangular cross-section and provides two side walls or surfaces 3, each joined along its lower edge to an edge of a base surface 1, and connected together along their upper edges by the bridge portion or raised surface 4 of the channel.

A pleat 5 having a V-section formed by strips converging towards each other extends continuously transversely of the panel; the parts or sections 5a that lie in the wing portions or base surfaces and the part or section 50 that lie in the bridge portion or raised surface 4 all project the same sense, being the sense in which the channel or enclosure 2 projects from the wing portions or base surfaces 1. The parts or sections 5b that lie in the side walls or surfaces 3 project in the reverse sense.

The configuration given to the panel permits it to respond by expanding or contracting overall in response to forces applied at, and perpendicularly to, the edges.

A and welding. In another, more than one piece of sheet metal may be used, the pieces being welded together along what are indicated as fold lines in FIGS. 1 and 2. it will be realized that a weld will be more rigid than a fold but, when welds are used, the areas lying to each side of the weld will provide some flexibility.

The use of a panel such as illustrated in FIGS. 1 and 2 is shown in FIG. 3 which illustrates a section through a furnace roof. The roof is lined by horizontal tubes 20. A row of inlet headers, of which one appears at 21, and a row of outlet headers, of which one appears at 22, extend longitudinally above the roof and superheater platens (not shown) extend between the roof tubes 20 from the inlet to the outlet headers. Two panels 23 and 24 such as have been described with reference to FIGS. 1 and 2, but each with several parallel pleats each spaced from the next along the length of the panel, are disposed one above the row of inlet headers and one above the row of outlet headers with the headers lying in the channel of the associated panel.

Roof supports 25 extend parallel to each other longitudinally of the roof and a casing sheet 26 extends alongside each support 25. The edge of the sheet 26 remote from the support 25 is reinforced by a strengthener 27 that lies on the roof tubes 20 while the edge nearest the support 25 is upturned and welded continuously along that edge to the support 25. Panels 23 and 24 rest on the casing sheets 26 and beneath each pleat, in alignment with the pleat, a slit of the same width as the pleat is formed in each casing sheet 26 extending back from the edge of the sheet remote from the support 25 to to the edge of the panel. The panels are then welded continuously along their edges to the casing sheets. To close the ends of the pleats, inserts of U- shaped cross-section are used with one face welded flat across the end of the plate and the other connected to the support 25.

At the ends of the roof, the ends of the casing sheets are connected together by further casing sheets (not shown). Plates welded around their edges to the ends of the panels 23 and 24 meet, and are welded to, these further casing plates.

In the construction illustrated in FlG. 3, both the channels of the panels and the pleats accommodate expansion of the panels resulting from movement occuring during operation of furnace in the support bars and other constructional element of which the furnace is formed. Such movement will also occur relatively to the pipes 30 and 31 connected to the inlet and outlet headers respectively and the construction is such that two pipes are disposed between each pair of pleats. In addition to the movement permitted by the channels and pleats, some distortion of the other parts of the panels and of the casing sheets can also occur.

What is claimed is:

1. An improved expandible metallic panel subjected to thermal expansion and contraction and having at least two base surfaces lying in a generally flat common plane and one raised surface lying in a plane generally parallel and displaced from the plane of said base surfaces, adjacent edges of said raised and base surfaces being interconnected by side surfaces each lying in a generally flat plane substantially normal to said raised and base surfaces, the raised and side surfaces cooperating with each other to form a channel of generally rectangular cross-section, at least one pleated portion extending transversely across said raised, side and base surfaces, said pleated portion being of substantially uniform triangular cross-section throughout its length and divided into a plurality of sections having their apex lying in the same plane, each of said sections corresponding to one of each of said panel surfaces, the pleated sections associated with the raised and base surfaces projecting outwardly thereof and the pleated sections associated with the side surfaces projecting inwardly thereof, and said channel having a crosssectional area substantially greater than that of the pleated portion.

2. An expandible metallic panel according to claim 1 wherein said channel and pleated portion are formed of a folded continuous sheet of metal.

3. An expandible metallic panel according to claim 2 wherein at least one of the fold lines of said channel and pleated portion is shaped along a slit formed in the metallic panel and the panel edges bordering said slit are weldably joined together.

4. An expandible metallic panel according to claim 1 wherein the panel surfaces are formed of separate sheets of metal arranged in edge-abutting relationship, said abutting edges being weldably joined to one another.

5. An expandible metallic panel according to claim 1 including at least two spaced parallel pleated portions and at least one opening extending through that part of the raised surface lying intermediate of said pleated portions. 

2. An expandible metallic panel according to claim 1 wherein said channel and pleated portion are formed of a folded continuous sheet of metal.
 3. An expandible metallic panel according to claim 2 wherein at least one of the fold lines of said channel and pleated portion is shaped along a slit formed in the metallic panel and the panel edges bordering said slit are weldably joined together.
 4. An expandible metallic panel according to claim 1 wherein the panel surfaces are formed of separate sheets of metal arranged in edge-abutting relationship, said abutting edges being weldably joined to one another.
 5. An expandible metallic panel according to claim 1 including at least two spaced parallel pleated portions and at least one opening extending through that part of the raised surface lying intermediate of said pleated portions. 